michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_LOCATION_H_
michael@0: #define BASE_LOCATION_H_
michael@0: 
michael@0: #include <string>
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/basictypes.h"
michael@0: 
michael@0: namespace tracked_objects {
michael@0: 
michael@0: // Location provides basic info where of an object was constructed, or was
michael@0: // significantly brought to life.
michael@0: class BASE_EXPORT Location {
michael@0:  public:
michael@0:   // Constructor should be called with a long-lived char*, such as __FILE__.
michael@0:   // It assumes the provided value will persist as a global constant, and it
michael@0:   // will not make a copy of it.
michael@0:   Location(const char* function_name,
michael@0:            const char* file_name,
michael@0:            int line_number,
michael@0:            const void* program_counter);
michael@0: 
michael@0:   // Provide a default constructor for easy of debugging.
michael@0:   Location();
michael@0: 
michael@0:   // Comparison operator for insertion into a std::map<> hash tables.
michael@0:   // All we need is *some* (any) hashing distinction.  Strings should already
michael@0:   // be unique, so we don't bother with strcmp or such.
michael@0:   // Use line number as the primary key (because it is fast, and usually gets us
michael@0:   // a difference), and then pointers as secondary keys (just to get some
michael@0:   // distinctions).
michael@0:   bool operator < (const Location& other) const {
michael@0:     if (line_number_ != other.line_number_)
michael@0:       return line_number_ < other.line_number_;
michael@0:     if (file_name_ != other.file_name_)
michael@0:       return file_name_ < other.file_name_;
michael@0:     return function_name_ < other.function_name_;
michael@0:   }
michael@0: 
michael@0:   const char* function_name()   const { return function_name_; }
michael@0:   const char* file_name()       const { return file_name_; }
michael@0:   int line_number()             const { return line_number_; }
michael@0:   const void* program_counter() const { return program_counter_; }
michael@0: 
michael@0:   std::string ToString() const;
michael@0: 
michael@0:   // Translate the some of the state in this instance into a human readable
michael@0:   // string with HTML characters in the function names escaped, and append that
michael@0:   // string to |output|.  Inclusion of the file_name_ and function_name_ are
michael@0:   // optional, and controlled by the boolean arguments.
michael@0:   void Write(bool display_filename, bool display_function_name,
michael@0:              std::string* output) const;
michael@0: 
michael@0:   // Write function_name_ in HTML with '<' and '>' properly encoded.
michael@0:   void WriteFunctionName(std::string* output) const;
michael@0: 
michael@0:  private:
michael@0:   const char* function_name_;
michael@0:   const char* file_name_;
michael@0:   int line_number_;
michael@0:   const void* program_counter_;
michael@0: };
michael@0: 
michael@0: // A "snapshotted" representation of the Location class that can safely be
michael@0: // passed across process boundaries.
michael@0: struct BASE_EXPORT LocationSnapshot {
michael@0:   // The default constructor is exposed to support the IPC serialization macros.
michael@0:   LocationSnapshot();
michael@0:   explicit LocationSnapshot(const tracked_objects::Location& location);
michael@0:   ~LocationSnapshot();
michael@0: 
michael@0:   std::string file_name;
michael@0:   std::string function_name;
michael@0:   int line_number;
michael@0: };
michael@0: 
michael@0: BASE_EXPORT const void* GetProgramCounter();
michael@0: 
michael@0: // Define a macro to record the current source location.
michael@0: #define FROM_HERE FROM_HERE_WITH_EXPLICIT_FUNCTION(__FUNCTION__)
michael@0: 
michael@0: #define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name)                        \
michael@0:     ::tracked_objects::Location(function_name,                                 \
michael@0:                                 __FILE__,                                      \
michael@0:                                 __LINE__,                                      \
michael@0:                                 ::tracked_objects::GetProgramCounter())
michael@0: 
michael@0: }  // namespace tracked_objects
michael@0: 
michael@0: #endif  // BASE_LOCATION_H_